x+3.2＝4.6
x=4.6-3.2
x=1.4
x-1.6＝4
x=4+1.6
x=5.6
15-x＝2
x=15-2
x=13
1.6x＝6.4
x=6.4÷1.6
x=4
15-x＝2
x=15-2
x=13
2.1÷x＝3
x=2.1÷3
x=0.7检验啊检验啊hh